The current status of remote diagnosis of von willebrand disease in children in Russia

Abstract

The diagnosis of von Willebrand disease (vWD) in children remains a challenge in many regions of our country. This encouraged the Russian Hemophilia Society to create, in 2019, a special diagnostic programme offering remote diagnosis of vWD to patients in regions. Objectives: An interim evaluation of the effectiveness of the programme for remote diagnosis of vWD in children. The study was approved by the Independent Ethics Committee and the Scientific Council of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of Ministry of Healthcare of the Russian Federation. Under this programme, if advised by a hematologist at the place of residence, a patient's peripheral blood was collected, frozen and sent to the Clinical Hemostasis Laboratory at the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology. Over the period from 11.04.2019 to 07.08.2020, we received 72 frozen peripheral blood samples from children under the age of 18 sent from 21 regions of the Russian Federation. Von Willebrand factor (vWF) ristocetin cofactor activity, vWF antigen levels as well as coagulation factor VIII activity were measured. Out of the 72 samples, only one (1.4%) was inadequate. Reduced vWF activity (30–50%) was observed in 16.7% of cases, and another 16.7% of patients had vWF activity < 30%. VWF antigen levels were 30–50 % in 13.9 % of patients and < 30% in 9.7% of cases. Among the patients with vWF activity < 30%, 1 patient (8.3%) had type 1 vWD, 10 patients (83.3%) – type 2 vWD, 1 child (8.3%) – type 3 vWD. Six children (8.3%) demonstrated reduced factor VIII activity while maintaining normal vWF activity and antigen levels. The coagulation factor VIII activity/vWF antigen ratio was decreased in 8 children (11.1%). The vWD remote diagnosis programme has allowed us to detect abnormalities in 30 patients (41.7%), 16.7% of whom demonstrated laboratory features characteristic of vWD. Eighteen children (25%) require further, more comprehensive laboratory testing. This programme has great potential, especially in underpopulated regions where the development of local diagnostic capabilities may not be economically viable.